SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '578b69b1f02db66164ef1a21f91cb037d0404497c9cafa354530586c52aaa625' 
  AND token = 'iMDxxNxYZEx2pdY11uIfDrBoh9CjOgMLtUhD8wKhr9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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