SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47282b4c02228ee79bcda62c33bc98183d898726306cfa309386441d8c8bc1d6' 
  AND token = '1j+2VajwwHRIQhGGXeWLDWO9atEg3/JOIFBguhGmZ/Y=' 
  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"
    }
  }
}