SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '509d3a22abd70e1b5232b5242ff12ed4707ed75b0d27443d130686a987c956d2' 
  AND token = 'iLBdmIBJG+yYv1lOfQii/2tZAyL7FyPmnVk7kyRbAfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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