SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5341af061184e2eee5c4dd1ecfe3ee686da8c37f897077de03700165161908f5' 
  AND token = 'W3UaHED63aoepnWDm3AI8K/PbhvlkgSIl+Q7DCeSWKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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