SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37d181b8c2142dbdfb4569fc12b467e6928a283c772af7fd07fe54e505d4d2de' 
  AND token = 'Po7ar14ZrM7wylLUY4FrYmzSK6T6KPWEHZlcoGg+e/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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