SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c88fe60e606d7c47ce501a32a69eb0b0c7df3b6d2868ec01091b5a496c9887f3' 
  AND token = 'Jzllpdp79kGi7H7w4jjZuZv7BVq4OZHHrqHtl2VK3oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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