SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c853fbccb3ee37004f95981bc375f591e5b22ea4c1187e0eb298168b3c3e10f4' 
  AND token = 'Bxk9FtPtYEEEhYzAOmlR0JyW3VueNNUOgLNUQtI60bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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