SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d88f9fe92c4829a498b92cceea0d3ddf70cb330ce8a10aa61f8722f78939b0b' 
  AND token = 'O4gLf8MG9+/2T1tPQJqfgYGR3+/0V9oLT1p3JGqNjEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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