SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2679994e380f679aefca78914a0a2a391a40d77e4764cbad87a5198c413d812' 
  AND token = 'bUYP9Yr6onOoxP3tW/4ulpktxctqsFme3BsIeBYCKGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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