SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7fca9f15d63b060789de34b0b8a2fa1654f4c9cd1ff2d5bf2378c3ca598656d' 
  AND token = 'owPEitO6SILyrnT4ptZMBrKFVGfE4LmvXWOjehIFhis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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