SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '084c835b22242d5a99ce69df9cccc87ced21ef5d08472d4ebddaa70c6cad929c' 
  AND token = '20/p+9heil3cDyHDRJiipPNdm2CN7z1Ke8SZ0NtQvuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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