SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0db1bb396f38f0699a5ee561eb5a124c613c61071d2ce0618c5e5a279b20481' 
  AND token = 'iaKmxG9sYMXFllH+HkKyuADfjgsZqgB3tcCk4Qznxtc=' 
  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"
    }
  }
}