SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cba3a0a8ccf2cecfeccae8cc1b6e501d5b4a47a62ac9dab33cecefb47c69fa9c' 
  AND token = 'L5NxQx8MIYuF91KbZviuQzuwktMn5nP9Vg7I0itC0Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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