SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14dfa7f9e0f73fabcb6bfcb8321703b52e9ed809c8640877e5d00c373ea14bfd' 
  AND token = 'FDtcZWjccoDuqyjqc44NdxBqBmhM0urVhGzHDfQz0lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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