SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c25b2f685b2a10430864057bdd12f180132550cc0ce44b19d1b80bdaacad01b7' 
  AND token = 'kaD0kEe9DGxmswEg8efRfAjMhmLFpXNFodzRkHM06g4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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