SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e23995cc605419dbccdce8b652b55545d31e9b7c627aabf8fb87eca3d00c12e0' 
  AND token = 'ImsyRC7OnHtUckdUyRpG3zx78fMzRBm+2b6lOipDBto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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