SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18ad563e394c752316508e5f9c2956228dc9fd6a9aeb3b9ed17af7c201a01d6a' 
  AND token = 'TJP8lJcz4iOvXRQNmtsTo6rdGUBab7GzzgS+57T1gqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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