SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57e7cd82c1b206baa2138665521abed7e548d0f537e6871595299bb91ce8c87e' 
  AND token = 'ZzbySR98J4lgj8MZpR2Aal74fHA/BmD+qHnBpG7Qhv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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