SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2b8d3889c7a8ff3a664b472c62dd550eeeb09d03d00a3279f2c2b4c74738c8f' 
  AND token = 'dw1zKkwX+5Bo5jDwfTLhlSe9Pq6pYNT7OJ/zrSqbguY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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