SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934ef983c64ce264fc3da07cc4b4a5a9429ab1bd165cb8bbcc82570e6be653c3' 
  AND token = 'eZYzVys9csfYPJAZGeeyc7H1zFHh8STsIa18H3GTjnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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