SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab31f9b3e95f626edca6ba84617216ee511d9a3c9327b73eecff35edbbb15c03' 
  AND token = 'rWCw/zVGjwQC5VrQV7j1sRFYPsemxzSCxBV3j653mOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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