SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '694fea276cd62e0ac2578bf1704ae01f6688e18a36b0cabdde942a7d92e6508d' 
  AND token = 'qYcRXHkzmflK3iDn1XWcPms+AQ/C/z8BpU8cTrFvaTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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