SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a4bbfc75c09a274f4eae68c50be1e62d52c1bf9756a165697c6a83aecb36b92' 
  AND token = 'vhCxpDKZzqACuszElbZfvKLVFLGYl3VQb6AjAdNr/3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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