SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68a7b928c15ed4b6888c1a96614356d7fa047ad05bd304253a4af221d0e8f44a' 
  AND token = 'E6a2wc+9zzY3gFr114AHWGXGIdUJ83bXsQ1kLj8YHhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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