SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd32c957e802a056762ad41ece380b11db9a32234cc256fb3d552f8371be010ad' 
  AND token = 'FqG713D1RG5SgaisEiXBR0gKIkKirypm4rQWDMZIpA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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