SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ef6d0fa170cc892de139341af13c0d25ff4d207247f1a9f6605c375b29b0dd6e' 
  AND token = '9K4ZWRLLUCqIDNgFco6gQGT14uhv1e+invsJJ/oSp14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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