SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed66e40350d48de56cb83691a7d21d2f516b73c90747d6eb1b25ba57991b5d44' 
  AND token = 'nySJmvcsBPHlT4gLPRoqnjw0PWaDYlAj2EDmd1uOBSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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