SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9ffa2fdc87b0fdcb1fe0c4d4c0827bf9140abf8b8a7458d2455266ae3f353ad1' 
  AND token = 'WOEVUHkUSuyMPgmDNkBWjkJpOAhgu6+sM01Dx3HbYHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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