SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f657150630d919f0d6ab1dad5964a8c35a69a185d00167ea95590e88ca550a51' 
  AND token = 'chEmcQW2LsU1aGGm7qRJa19c5qZvdrN1qzZ/n6juUmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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