SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '200d581205c9166f9061758682a2fd7d87db0fb9c874e317631bc9d2374cddc5' 
  AND token = 'nTHI4QsAvjLeYLcGxPUxf95iOP+Pqy7Z+t9hF3ZdoCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}