SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac1959ed716e19c93138268836372f05fb142729fbffb893867d49b71558d8dc' 
  AND token = '+CYGskCn4u5BBwHO1Yz57a8m+Sd8x/Kx+yuWz4Z8xSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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