SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44162ae08a5d82a10d0648b839b17a7fbb2662001ee72115cf13d4386b90da3f' 
  AND token = 'NgJf17NIBWDI8Bpg5SwYU8G7Bql+/UCjZnxcJRgplvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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