SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba1efcdb81874910dd672569267c4967506dd2a6dd4d34ece1e58e223c5a0fa9' 
  AND token = '8sw6GJ+3AEzpNk2DTKF4FoaMKd6qqNQZrjlUTH1k/CY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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