SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e94273492539184304f9ec4626016baa4c8a205e640e846d0951d4e10abdc58a' 
  AND token = 'AHi7ozxwPFc9ORnmjd3gb0enp6Nk8pZE/TCO05JFlU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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