SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a4e5c1b76119e0444fc2852ca4c55d45850146c1141d6b47ce54bc30faf4a72' 
  AND token = '03Fm24dxYrlXmmQFUbgRWg6cSj+kEyvIDATW+oOdgRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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