SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43eb5a1136b6a8fa6d19ce9161682cb169c18f4ca7b692551b0c4a54aa53a3f5' 
  AND token = '0tCi/U1IlW42xMtcgIXR3PJX12CF+NKcu0NZDW3jTOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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