Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818bece0db06d67a08f15ecc65416f289fdc0244f0f5b9762034b93a4cfbd350' 
  AND token = '6y336XlDNP4ytvLsfep7ABrlpH8pK08OYxMmTDWZnBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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