SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e17088fea052717df0889c274ad0a12f81a8ddd1cb662f62932c2f8568839df6' 
  AND token = 'EQiONNOoKMb5U94FYHaiBRhMm9EaQ9AAjpEL/QA9kvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}