SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73daf2e15201ad7844b2f54720bd7168f16a1b2199e73b17e3052e0a3f6644fe' 
  AND token = 'emqrqb7zAme8sARsqow3sA0zJQHxWTbi0qlXbOiJ5NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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