SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db84bce4ac5e51bf236f509daf288a0afa1899d7030ce060e846138df2a9ae9' 
  AND token = 'Ry7afwTkthadnzlihQoYgiC0S931t+lMzvtztZ7LfI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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