SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfcddb6757b3467c0c791cfb966303c94a5fffb65c88df59e4a6f1b2e84280b9' 
  AND token = 'QJ344qsivPmtyMHb7wGQ5J+Z8uAWntKdzkoovwSF6ZY=' 
  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"
    }
  }
}