SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdb278847772d908ccce976888457225e97d1c9db105f993228f12285668393b' 
  AND token = 'spgOqLDkX0t2kuhYm0tNrrLx7sDKInrCmMf0dFTDdp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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