SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '841b697323711a84010901d8707c2304a510d279b26d432451b94e79ccccd663' 
  AND token = 'pIZLbfyH23shn3OLDvE0mMvcnDrVSoQRqXA8y6W2ek8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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