SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7772514a0b1ba96d800d3d80df490c3160119a87081c2867b7311d2aac6ae846' 
  AND token = '4LDS9jHP2sgmdHXUcaWkfuGDOX2L7TlEQ5HWugVuGtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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