SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c83a5c7c0e297e465a80fb03c0201dc299774180ae15a3e3f587194da40b60ae' 
  AND token = 'VRXkVC9EKFwfFGUXHqwQUA3QBv2FX7FGuGbUKN55vac=' 
  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"
    }
  }
}