SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a2997710460fde3f44cf5752f9ad9dd356d32b16704b6af0c567685dce5cc8' 
  AND token = 'iWALbzuEDH7jJ/gDN9rvMlgIGKkZeVS8x8vkOjRTDLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00081

JSON explain

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