SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf7ff33842bd523f5e31c6c005602d96c924c932eddd9bcfc6d956f17f5da87a' 
  AND token = 'Dr2SFJ9GwM5G8yyGjTyfHybn8MqbUMPTJWbHMscCrHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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