SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5c94565b0f4458a4d4c2eb5475b846d8d9c242add0bc199e29cf8bb8bcab405' 
  AND token = 'i2Nud6Tf5LBCgr05Z5Hv1scyQ6SLgjuB7RWWqGi3k1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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