SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d02f46395be739a7fd9403128e217feb439bb269d991773d4bdebfbd023fb6c' 
  AND token = 'UqilM8ATdalwM3GMAvLV86aSqECGfE99epvsVawUXQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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