SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5ca57cf0871e06e5d5e139d4996163532152450523fc165179b312318654cc9' 
  AND token = 'c2ybokUXWzcbNZbYaQGESD4ZoJUVgg33/tUj7E1Kjyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}