SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9666cbd01a66a7f8934bfbc747097c21e8dd7714e0b793be4ac1bd8c5ed0da75' 
  AND token = 'V5qsv52onTD9GBue3wsqZtALeDiUFZpMcI0FCJrjurc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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