SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75cf18562ac167865ac93317ceb39263e14e8c28d9bb50b79177204c218be727' 
  AND token = 'ihYtaikIVDi6xI0i4J78S5wepEyjcQ79f4p6Sv80nzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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