SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44fc0ce8464628fc03e4f15c97ee4a3ae80933932ff0bf5ca211bc90aa686928' 
  AND token = 'eR9ouk8/p2vgeai/yOJnxiQCiNtnbBXu1jWRmDNF4Uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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