SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0246b52683f136be9da00084755781a4a6d9094cef219e1cc7999447a1a0590' 
  AND token = 'v0kA4gNgplvnvRPlku4ufXbeh6vD00h4Aia5tM4tuIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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