SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db9e179f05f00b36eddc8a314763138d8f07c8edb0dd1cadf4d3b4be9f528518' 
  AND token = 'B2DjYOFqGvSLlSbJ7FxWrFkkVtKH67jpVFj7Fm+4SIY=' 
  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"
    }
  }
}