SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153efcff3ddf2a462d06e7600f37b7b6ca77093f77a6bb82826f7530bb671880' 
  AND token = 'GTsRNEsHnTXKm8MGJxD4gQR+vw38akTEhEPZtLCwDco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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