SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd724107323c6c7e9248a02afc28cd649ba09eeb5a92f075245ae427de87cebf0' 
  AND token = 'f5jU1Xn4TdAk7rapiKRovXrpE1LWTBR4HTKgotzmo88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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