SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5cb7c279368d42b020aa6e1b91d4c1d116c99cb43e5f168e843f538e4ac59f7' 
  AND token = 'RumlWz/FwwdvHveGM51orJFsERiqVSl6qApiB7HK9LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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