SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7d48939d26dfca9eda7658406dba77384a6e2a70c9ea52e2a02168912142e4a' 
  AND token = 'VfdqZtSwk7vWTxdxQf0ICLxB0vGsCdOYC/qjueGEod0=' 
  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"
    }
  }
}