SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec738cb9ef4120db35608ef4a9dd4b3efe0ca832719c72596dbef66b3619048c' 
  AND token = 'M1WzgU8ryD7UEi8c5V4v0WXXG772ZwtNKppm9Vg3Cjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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