SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '053a30c8070a5f0a56541f956b70eca5ef98c267d75781e06ade949e4082e554' 
  AND token = '7V/UY9F11ssJ0XwIqABRozeJVVsgMoIpN6aZfvyK2Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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