SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89ca49c564885d3c45bf5a78f464ae4e795e0f108cd1de3d122b76493b1c3ab5' 
  AND token = 'eQuWZx73l+Wbf1cBPBBOnwBbscPOWTrvKAelZ6ThmYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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