SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98718d5509c25aac341f13c7e7cbfe5e0909742ceccc8580bd7967e635601238' 
  AND token = 'bNtfB6fy30Fo2eYyBA8qxDTt00Ly6zsbbvtNOO/t3Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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