SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4afc00af676fa92a4d2f55782d1eeae80023e760961d8bb9c942ff24318b7344' 
  AND token = 'EkpQIUe0zel5CXD8HQArxp2ALTvLP/PKqp1AuB89Uqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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