SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '586fcec1974739a183d2987f0c22cb6fd63d7194eea67b768a6f21a9bc2a566d' 
  AND token = 'nl/MQwNJ1fNQ1efgITzxJcJlnB3Ge1JaiCpq6xTuOUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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