SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '487f4146982529c7c80d1f8733cfa2921cce64ff911af08635157e4b97b2c758' 
  AND token = '82rYgJzDFHcwJpnsEbPGev9sxqcItqUTaDft/G2fFVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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