SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f4517fc47251e419d26b6fc8a8a1e434b6eeba6b7dde660e160e8dd03ec95e9' 
  AND token = 'LJ/U0Hkiujn0bxMfXkqbAWFLrHhEVpUgbbZCMdIxr5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}