SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f87449615eab6e4fb67fdc1e3cc5b2d7d3921a0c9b53dc30c7369232d624c3e' 
  AND token = 'DKEUZNjvHUAOgAqpbkTJLRVCELssdixtyao7o70cNiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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