SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20aac5da98b2737fae2feffd4573fd36bd6d7a4fbfdef51eea2c674a856ebd11' 
  AND token = 'Guoqo0NXwjdie6UybexXtJB026bM8ZmXH4foCEctezg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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